In LTE (Long-Term Evolution) Release-8Release-9Release-10, a plurality of PUCCHs (Physical Uplink Control Channel) is defined, such as a PUCCH Format 3 channel. Among them, the PUCCH Format 3 channel is used for transmitting hybrid automatic repeat request acknowledgement (HARQ-ACK) information, and thus can support the transmission of 1 to 20 information bits. However, when schedule request (SR) information and HARQ-ACK information are transmitted in one subframe at the same time, the PUCCH Format 3 channel can at most support the transmission of 21 information bits.
Here, the PUCCH Format 3 channel is taken as an example. User equipment (UE) firstly performs RM (Reed-Muller) channel encoding on bits of the HARQ-ACK information and those of possible SR information (that is, the bits of hybrid automatic repeat request acknowledgement and schedule request information (HARQ-ACKSR information), including the HARQ-ACK information or the HARQ-ACK information and the SR information), and then performs scrambling, Quadrature Phase Shift Keying (QPSK) modulation, block-wise spread using an orthogonal sequence, cyclically shifting, transform precoder (also called as DFT precoder), and mapping of Physical Resource Block (PRB). A baseband sending signal obtained through Single Carrier Frequency Division Multiplexing Access (SC-FDMA) baseband signal generation (also called as IFFT transformation) is emitted via medium radio frequency. An evolved Node B (eNB) receives an emitted signal and performs demodulation according to the above process, thereby obtaining bits of the HARQ-ACKSR information through decoding.
The UE measures a downlink channel, and obtains Channel State Information (CSI) of the downlink channel, wherein the CSI includes information such as Channel Quality Indicator (CQI), Precoding Matrix Indicator (PMI), and Rank Indication (RI). The UE feeds the CSI back to the eNB which employs the CSI to perform downlink data scheduling. Specifically, the fed CSI can be divided into periodic CSI and non-periodic CSI, or can be divided into the CSI fed on the PUCCH and the CSI fed on the PUSCH (Physical Uplink Shared Channel).
In some configurations, when the periodic CSI and the HARQ-ACK/SR information are transmitted in one subframe at the same time, the periodic CSI will be discarded because the greater the number of downlink carriers, the larger the number of the periodic CSI to be configured, and the greater the number of subframes occupied by the periodic CSI, the higher the possibility that the periodic CSI and the HARQ-ACKSR information are transmitted in one subframe, and the more frequent the periodic CSI is discarded under the circumstance where the number of the subframe occupied by the HARQ-ACKSR information is constant. Therefore, such situations shall be taken into consideration in case of eNB scheduling, the scheduling complexity is increased and a downlink throughput capacity is lost.
To this end, there has been proposed a scheme which supports the simultaneous transmission of the periodic CSI and the HARQ-ACK/SR information on the PUCCH Format 3 so as to reduce the situation where the periodic CSI is discarded and enhances downlink transmission performance. There are mainly two schemes: joint encoding and independent encoding. As shown in FIG. 1, the so-called “joint encoding scheme” means to cascade-multiplex the periodic CSI and the HARQ-ACKSR information before channel encoding, and then perform joint encoding uniformly, finally make the periodic CSI and the HARQ-ACK/SR information subjected to the above processing of the PUCCH Format 3 channel. As shown in FIG. 2, the so-called “independent encoding scheme” means to independently perform channel encoding and rate matching on the period CSI and the HARQ-ACKSR information, and then interweave the periodic CSI and the HARQ-ACK/SR information after channel encoding by an interweaver, finally make the periodic CSI and the HARQ-ACKSR information subjected to the above processing of the PUCCH Format 3 channel. Since the PUCCH Format 3 channel can only transmit 48 encoded bits (that is, 24 symbols after QPSK encoding modulation), how to respectively perform channel encoding on the periodic CSI and the HARQ-ACK/SR information is a problem to be solved.